Goal exclusively revealed in September that the Germany international had opened talks with the Gunners over a new deal, with his current contract expiring in 2015.
The 29-year-old joined Arsenal in August 2011 and initially struggled to adapt to the pace of the Premier League - but he is now showing his best form having struck up a solid partnership with Laurent Koscielny.
|3/1||Arsenal are 3/1 with Coral to be the top London club this season|
"I am very happy here," he is quoted as saying by the Evening Standard. "The first year was tough for me, a very tough challenge, but the club and the manager always trusted me in a special way.
"I got a big injury in my first year, so I took my time to settle down completely and there were a lot of reasons.
"I think it is a little reward that we are talking [about a new contract], because I still have one-and-a-half years left. There is no rush but it seems that some people are delighted with my performances at the moment. I am pleased with the situation.
"It took me a while to get to that level. But the manager always trusted me and said I was intelligent enough to cope with problems."
Arsenal have benefited from Mertesacker's upturn in form and currently top the Premier League table.