(Sharecast News) - Investment platform AJ Bell delivered an impressive pre-close trading update on Thursday, with customers numbers rising by 12% and net inflows surpassing the £4bn mark against what it called a "challenging market backdrop".

The company, which offers ISAs, self-invested pensions, savings and dealing accounts, saw shares rise nearly 2% to 259.14p by 0825 BST.

Customer numbers for the platform business, which serves both advised and DIY investors, totalled 476,532 in the year ended 30 September, up 50,880 on last year, with advised customers rising 10% to 159,256 and D2C customers jumping 13% to 317,276.

Platform operations experienced "robust asset flows across the platform" during the period, with net inflows coming in at £4.2bn, though down from £5.8bn previously. Assets under administration rose 11% to a record £70.9bn.

Meanwhile, in the Investment division, net inflows surged 57% to £1.65bn, with assets under management jumping 68% to £4.7bn.

"I am pleased to report another year of continued organic growth for AJ Bell," said chief executive Michael Summersgill.

Summersgill said the company is continuing to engage with the government on potential reforms to ISAs, as it wants to "simplifying the existing ISA landscape to make it easier for retail investors to navigate".

"The long-term growth drivers of the investment platform market remain strong, and we look forward to announcing the annual results for what has been another successful year for AJ Bell in December," he said.