The chain, which has Glasgow roots, reported that in the six months to July 27, its like-for-like sales, excluding value added tax, grew 3.3%.
But while gross margins ticked up 60 basis points to 35.5%, adjusted earnings before interest, taxation, depreciation and amortisation (EBITDA) remained level at £7.5 million.
In the most recent eight weeks to September, like-for-like sales were ahead 1.1% but it also reported a 100 basis points rise in its gross margins.
John King, chief executive of House of Fraser said: "We are pleased to report another solid set of results with increasing success in our key areas of online and house brand development. We took deliberate action to continue to invest in our multichannel and house brand businesses, which has meant higher costs in the first half resulting in EBITDA being level. However, we expect that this investment will deliver growth for the second half."
In the first half of its financial year, House of Fraser reported a 57% rise in online sales with its "click and collect" system, where customers go to stores to get their orders, also helping to attract more customers into its outlets.
House of Fraser has made a major push into multichannel or online retailing with recent developments including a cut-off time of midnight for next day evening delivery as well as the launch of a mobile site.
Two years ago House of Fraser opened its first buy and collect concept store in Aberdeen. It also has an outlet in Glasgow, two in Edinburgh, including Jenner's, and a Jenner's store on the shores of Loch Lomond.
It used to have a larger presence in Scotland but stores in Aberdeen, Perth and Dundee were closed a decade ago.
The promotion of house brands such as Linea and Howick has the advantage of giving more generous margins than those on sales of third-party goods.
The results come as House of Fraser is expected to seek a stock market listing, which would be the third in its 164-year history.
House of Fraser was bought seven years ago for £351m by Icelandic group Baugur, which filed for bankruptcy in 2009.
The Icelandic government owns 49% of the shares, while Sir Tom's West Coast Capital has a stake of 11%.
Mr King said: "We remain confident that the group's business model, with our premium brand positioning, growing house brand mix and multichannel operations, positions us strongly for the foreseeable future."