The United Kingdom is slipping down an international school league table, says a global education survey.
The UK has fallen from 13th to 22nd in a school league table of 16 year olds
The survey, published by the Organisation for Economic Co-operation and Development, shows that too many pupils in the United Kingdom are leaving school with poor qualifications.
In a league table of 30 developed countries, including many of the UK's economic competitors, the UK has fallen to 22nd place - down from 13th place a generation ago.
The best record for pupils achieving good qualifications at the end of secondary school is Korea, followed by countries including Norway, Japan, the Slovak Republic, Switzerland and Sweden.
In contrast, the UK's academic record at the upper end of secondary school is above Turkey, Mexico and Spain, but below a mid-table group of European countries, including Belgium, Greece, the Netherlands and Ireland.
The figures, published on Monday, look at the qualifications held by different age groups - and the current ranking is based on those who have recently left the education system - the 25 to 34 year olds.
The previous rankings, in which the UK was in the top half of the table, were based on 55 to 64 year olds, who mostly left school in the 1960s.
The OECD says that this is not so much the UK getting worse, as other countries improving - with the UK failing to keep pace.
In particular, the OECD highlights the problem of too many youngsters in the UK dropping out of education at the age of 16.
While the international trend is for pupils to stay in education beyond the age of 16, the UK has had a longstanding problem with a relatively low staying-on rate.
And the OECD says that in an economy with reducing prospects for the unqualified, these school drop-outs could face poor employment prospects.
The government has recognised the problems with drop-out rates and School Standards Minister, David Miliband said:
"This is an important challenge. We have one of the highest university graduation rates but also one of the highest drop-out rates at 16.
"Despite progress since 1997, opportunity is still too often defined by birth not worth. The drive to raise standards in secondary schools is key to staying on.
"In addition, Mike Tomlinson, the former chief inspector of schools, is looking at the 14-19 years in education. One of his top priorities is how to stop so many pupils leaving schools at 16 with no or poor qualifications."
The survey also examined how much money was being put into education systems, both by the public and private sectors - looking at the proportion of national income spent on education.
Pupils who leave school early face poor employment options, says survey
The United Kingdom, based on 2000 figures, spent 4.5% of GDP (gross domestic product) on education, below traditionally high-investing countries such as Denmark, Sweden and Norway - but above countries such as Germany, Japan and Spain.
But the figures showed that overall national investment could be very different when private funds for education were included, in addition to state spending.
Both Korea and the United States draw large amounts of private money into education - and when this was included in the proportion of GDP, it showed that these two countries spent the most on education, with 7.1% and 7% respectively.