Warner Bros films have claimed the lion’s share of the record $4.2bn summer box office days before the season comes to an official close with the Labor Day weekend.

The studio took a 23% chunk out of the seasonal box office, closely followed by Paramount on 21%, according to fresh data from Nielsen EDI for the period May 1-August 31.

The top ranking is unlikely to change over the next four days, although the share may climb slightly in Warner Bros’ favour given that its horror release The Final Destination enters its second weekend in second place. Paramount has no film in the top five and, like Warner Bros, no new release this weekend.

Harry Potter And The Half-Blood Prince was the key driver for Warner Bros oand has amassed $294.3m by August 31. The studio released 15 films throughout the summer and also enjoyed great success with The Hangover on $270.2m.

Leading the way for Paramount’s nine releases was Transformers: Revenge Of The Fallen, which on $399.4m remains the biggest performer in North America so far this year. Also deserving mention are Star Trek on $256.7m and the still active G.I. Joe: The Rise Of Cobra on $132.2m.

Walt Disney Studios released 11 films and finished third on 14.5% market share, thanks to the $289.6m performance of Up. Fox released ten and placed fourth on 14.2% with Ice Age: Dawn Of The Dinosaurs taking $193.3m, while Sony and Universal placed fifth and sixth on 12.6% and 8.3% share, respectively.

The top performer of Sony’s eight films was Angels & Demons on $133.4m, while District 9 stands at $93.4m and has a shot at crossing $100m this weekend. For Universal, which released 11, the biggest release was Public Enemies on $97m.

The late summer success of The Weinstein Company’s Inglourious Basterds meant the company, which released three films during the season, ranked seventh with 2.1% market share. Quentin Tarantino’s film stood on a little more than $73m by August 31.

Rounding out the table was Fox Searchlight in eighth place with 1% market share. It released six films, the biggest of which was 500 Days Of Summer on $25.2m.

Nielsen said the top film from each of the above distributors accounted for 37.4% market share. A total of 318 films were released through all distributors during the May 1-August 31 period.