SPARK Energy, the fast-growing electricity and gas supplier based in Selkirk, has secured a further £200,000 of funding from the Scottish Investment Bank.

The latest tranche of funding from the investment arm of taxpayer-backed Scottish Enterprise was announced yesterday as First Minister Alex Salmond visited Spark Energy's headquarters.

Mr Salmond noted the Scottish Investment Bank had, to date, invested £855,000 in Spark Energy, which supplies gas and electricity to the residential letting sector.

Chris Gauld, promoted in the spring to succeed Spark Energy founder and Canadian-born entrepreneur PJ Darling as chief executive of the Selkirk company, recently underlined the firm's ­expectation that turnover would rise to about £80 million in the financial year ending this month, from £40.7m in the prior 12 months. He forecast the workforce would rise through the 250 mark in the next financial year with the recruitment of about a further 40 staff.

The Scottish Government noted yesterday that, in the 2014 Which? Switch energy satisfaction survey, Spark Energy outranks all of the "big six" providers.

Regulator Ofgem announced on June 28 last year that it was investigating Spark Energy's compliance with its gas and electricity supply licences and the Gas and Electricity (Consumer Complaints Handling Standards) Regulations 2008.

Ofgem said then: "We launched our investigation in response to information from a range of sources, including consumer complaints, information provided by the company in response to Ofgem correspondence, and a Consumer Futures referral."

This investigation remains open.

A Spark Energy spokesman said yesterday: "The Ofgem investigation is into historic issues from two years ago. We have since invested £1.4m in our customer service experience, and were recently rated better than the 'big six' suppliers in a Which? customer service survey."